From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-return-44361-listarch-gdb=sources.redhat.com@sourceware.org>
Received: (qmail 57304 invoked by alias); 4 May 2015 21:12:41 -0000
Mailing-List: contact gdb-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gdb.sourceware.org>
List-Subscribe: <mailto:gdb-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gdb/>
List-Post: <mailto:gdb@sourceware.org>
List-Help: <mailto:gdb-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: gdb-owner@sourceware.org
Received: (qmail 57276 invoked by uid 89); 4 May 2015 21:12:40 -0000
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=0.6 required=5.0 tests=AWL,BAYES_00,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2
X-HELO: mga09.intel.com
Received: from mga09.intel.com (HELO mga09.intel.com) (134.134.136.24) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 04 May 2015 21:12:40 +0000
Received: from orsmga001.jf.intel.com ([10.7.209.18])  by orsmga102.jf.intel.com with ESMTP; 04 May 2015 14:12:38 -0700
X-ExtLoop1: 1
Received: from orsmsx108.amr.corp.intel.com ([10.22.240.6])  by orsmga001.jf.intel.com with ESMTP; 04 May 2015 14:12:39 -0700
Received: from fmsmsx106.amr.corp.intel.com (10.18.124.204) by ORSMSX108.amr.corp.intel.com (10.22.240.6) with Microsoft SMTP Server (TLS) id 14.3.224.2; Mon, 4 May 2015 14:12:38 -0700
Received: from fmsmsx108.amr.corp.intel.com ([169.254.9.122]) by FMSMSX106.amr.corp.intel.com ([169.254.5.29]) with mapi id 14.03.0224.002; Mon, 4 May 2015 14:12:37 -0700
From: "Chun, Eric Y" <eric.y.chun@intel.com>
To: "gdb@sourceware.org" <gdb@sourceware.org>
Subject: Conditional Breakpoints with Pointers
Date: Mon, 04 May 2015 21:12:00 -0000
Message-ID: <64E3233B30622847B1E5ED56D2C1DBF00CACDC9F@FMSMSX108.amr.corp.intel.com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-SW-Source: 2015-05/txt/msg00005.txt.bz2

in gdb, how do i set a conditional breakpoint depending on value of pointer=
 keeping in mind that i have to check if pointer is null before dereferenci=
ng pointer?

here is an example of code i'm trying to debug:
    #include <iostream>
    using namespace std;
=20=20
    int main () {
      int *i[10];
      int *j =3D NULL;
      int k;
=20=20
      i[4] =3D new int;
      *i[4] =3D 8;
=20=20
      for (k=3D0; k < 10; k++) {
        j =3D i[k];
      }
=20=20
      return 0;
    }

i set conditional breakpoint at line "j=3Di[k]" but i got a seg fault:
    (gdb) b 14 if j && *j =3D=3D 8
    (gdb) r
    Starting program: /nfs/blahblah/a.out
    Failed to read a valid object file image from memory.
    Program received signal SIGSEGV, Segmentation fault.

does anybody know why there is a segfault?